1. Field of the Invention
The present invention relates generally to a hard disk type detecting technology, and more particularly, to a hard disk type detecting circuit and a hard disk connecting port having the hard disk type detecting circuit, the hard disk type detecting circuit detecting whether a hard disk plugged into the hard disk connecting port is a SAS hard disk or a SATA hard disk.
2. Description of Related Art
Generally, a hard disk is plugged into a hard disk connecting port for establishing electrical connection with a computer device. The hard disk connecting port is further electrically connected with an indicator such that the hard disk plugging state can be shown through the lighting state of the indicator. More particularly, through a status interface that can detect the hard disk status, which is the eleventh pin (referred as P11), the hard disk connecting port can control operation of the indicator by switching on the indicator when the output voltage of the pin P11 is low and switching off the indicator when the output voltage of the pin P11 is high. Thereby, a user can know whether the hard disk is correctly plugged into the hard disk connecting port or not.
The current commonly used SAS hard disk connecting port allows a SAS type hard disk to be plugged thereto. In addition, the SAS hard disk connecting port also allows a hard disk of different type such as a SATA type hard disk to be plugged thereto. At the time a SAS type hard disk is plugged into the SAS hard disk connecting port, output signal of the pin P11 changes from a high voltage level to a low voltage level so as to drive the indicator to operate, thereby indicating the hard disk has been plugged into the connecting port. But when a SATA hard disk is plugged into the SAS hard disk connecting port, the output signal of the pin P11 will stay at the high voltage level, which accordingly cannot switch on the indicator. Therefore, a user cannot identify whether the SATA hard disk is correctly plugged into the connecting port or not. In addition, even if no hard disk is plugged into the hard disk connecting port, the output voltage of the pin P11 stays at the high voltage level, which is same as when the SATA hard disk is plugged into the hard disk connecting port. As a result, the computer device cannot correctly identify whether a SATA hard disk has been plugged into the hard disk connecting port only by the output signal of the pin P11. Therefore, the computer device cannot correctly identify the type of the hard disk plugged into the hard disk connecting port only through the voltage level of output signal of the pin P11.
Therefore, there is a need to develop a hard disk type detecting circuit for overcoming the above drawbacks.